A wireless sensor network (WSN) of spatially distributed autonomous nodes can monitor physical or environmental conditions, such as temperature, sound, pressure, etc. and cooperatively pass data through a wireless network to a base station (or sink node) for data processing.
Each node has typically several parts: a sensor, a radio transceiver with an internal antenna or connection to an external antenna, a microcontroller, an electronic circuit for interfacing with the sensor, and an energy source, usually a battery or an embedded form of energy harvesting. Size and cost constraints on the node result in corresponding constraints on resources such as energy, memory, computational speed and communications bandwidth. As such, energy saving is a problem for deploying the WSN.